I would kill for a Fox McCloud vanity costume (without the ears unless a race's species calls for it).
Yeah, but not that kind of ponies. I like the ones in Diablo 3. Don't you Mean Spartan Armor? The Mk.V?
I believe that it was called the MJOLNIR Powered Assault Armor, which goes to show that I played too much Halo in high school. That would be fabulous.
Armor/suit with some glowing lines and such similar to Tron. Poptop vanity set. Various animal ears. Various wigs (or a hair stylist npc).
And ALL of the masks in majora's mask. (rock, bunny hood, goron, majora's, fierce deity,) and all the transformations from them. so a goron outfit, fierce deity link.
Guy Fawkes mask Lamar hat from Half Life 2 Night vision goggles from Splinter Cell (although those might not be "vanity" since they have a use lol) My avatars hat! Those gag glasses with the plastic eyes are dangling from the frames Rainbow (color changing) eyes! or other vanity item that allows your eyes to look different (red, herobrine, etc.) A lot of items should be randomly assigned colors. Except for specific ones that actually reference things. But I like the idea of red, blue, etc. colored Spartan armor.